TWI406066B - Liquid crystal panel - Google Patents

Abstract

A liquid crystal panel includes: first and second substrates arranged to be opposite each other at a predetermined gap; a liquid crystal layer filled between the first and second substrates; alignment films; a counter electrode pattern formed on the first substrate; and a pixel electrode pattern formed on the first substrate so as to have a plurality of electrode branches, the pixel electrode pattern having a partial connection branch formed around a contact so as to transversely connect a plurality of electrode branches extending from the contact from among the plurality of electrode branches.

Description

LCD panel

The invention described in the present specification relates to a liquid crystal panel in which a driving method for controlling alignment of liquid crystal molecules is controlled in parallel with a substrate surface by a lateral electric field generated between a pixel electrode and a counter electrode. Moreover, the invention proposed in this specification has a surface as an electronic device on which the liquid crystal panel is mounted.

Now, in the panel structure of the liquid crystal panel, in addition to the vertical electric field display type in which an electric field is generated in the direction perpendicular to the panel surface, a panel structure corresponding to various driving methods has been proposed. For example, a panel structure of a horizontal electric field display type in which an electric field is generated in a horizontal direction on a panel surface is proposed.

In the horizontal electric field display type liquid crystal panel, the rotation direction of the liquid crystal molecules is parallel to the substrate surface. That is, in the liquid crystal panel of the horizontal electric field display type, the liquid crystal molecules have little rotation in the vertical direction of the substrate surface. Therefore, characteristics in which the change in optical characteristics (contrast, brightness, hue) is relatively small are known. That is, the liquid crystal panel of the horizontal electric field display type has a larger viewing angle than the liquid crystal panel of the vertical electric field display type.

Fig. 1 shows an example of a cross-sectional structure of a pixel region constituting a liquid crystal panel of a horizontal electric field display type, and Fig. 2 shows an example of a planar structure corresponding thereto.

The liquid crystal panel 1 is composed of two glass substrates 3 and 5 and a liquid crystal layer 7 which is sealed by being inserted. The polarizing plate 9 is disposed on the outer surface of each of the substrates, and the alignment film 11 is disposed on the inner surface. Further, the alignment film 11 is a film used to align the liquid crystal molecules of the liquid crystal layer 7 in a predetermined direction. Generally, a polyimide membrane is used.

Further, on the glass substrate 5, a pixel electrode 13 and a counter electrode 15 which are formed of a transparent conductive film are formed. The pixel electrode 13 has a structure in which both ends of the five electrode branches 13A processed into a comb shape are connected by a connecting portion 13B. Further, at the upper end in the figure of the pixel electrode 13, a rectangular contact portion 13C in which one portion of the electrode branch 13A and the connecting portion 13B are integrally connected is formed.

On the other hand, the counter electrode 15 is formed on the lower layer side (the glass substrate 5 side) than the electrode strip 13A so as to cover the entire pixel region. By this electrode structure, a radiation-like electric field is generated between the electrode branch 13A and the counter electrode 15. In Figure 1, this electric field is indicated by the dashed arrow.

Further, the pixel area corresponds to the area surrounded by the signal line 21 and the scanning line 23 shown in FIG. Incidentally, in each pixel region, a thin film transistor that controls the application of the signal potential to the pixel electrode 13 is disposed. The gate electrode of the thin film transistor is connected to the scanning line 23, and the control opening/closing operation is switched by the potential of the scanning line 23.

Further, the main electrode of one of the thin film transistors is connected to the wiring pattern (not shown) via the signal line 21, and the other main electrode is connected to the contact 25. That is, in the case where the thin film transistor is turned ON, the signal line 21 and the pixel electrode 13 are electrically connected.

Further, as shown in FIG. 2, in this specification, the gap between the electrode branches 13A is referred to as a slit 31. In the case of Fig. 2, the extending direction of the slit 31 is the same as the extending direction of the signal line 21. That is, the slit 31 is formed along the Y-axis direction in the drawing.

For reference, the cross-sectional structure near the contact point 25 is shown in FIGS. 3(A) and (B).

[Patent Document 1] Japanese Patent Laid-Open No. Hei 10-123482

[Patent Document 2] Japanese Patent Laid-Open No. Hei 11-202356

In the liquid crystal panel of the horizontal electric field display type, as shown in FIG. 4, in the both end portions of the slit 31 (near the portion where the electrode branch 13A is connected by the connection portion 13B or the contact point 13C), the alignment of the liquid crystal molecules at the time of voltage application Easy to disorder is known. This is because the contact portion is a rectangular electrode, so that the transverse electric field does not occur and the alignment control is weak. Furthermore, it is one of the reasons why the unevenness around the contact point is large and it is easy to become the core of the alignment disorder. This phenomenon is called disclination.

In Fig. 4, a region 41 in which the aforementioned misdirection is likely to occur is indicated by a diagonal net bottom. In the case of Fig. 4, the alignment of the liquid crystal molecules occurs in a total of eight regions 41.

However, when external pressure (finger pressure or the like) is applied to the wrong direction, the arrangement of the liquid crystal molecules is disordered, and as shown by the arrow in the figure, it has a characteristic of expanding along the extending direction of the electrode branch 13A. Further, the disorder of the arrangement of the liquid crystal molecules acts in a direction in which the alignment of the liquid crystal molecules is reversed in the direction of the electric field. This phenomenon is called a reverse twist phenomenon.

An example of the occurrence of the reverse twist phenomenon is shown in FIG. In Fig. 5, a region 43 in which the arrangement of the liquid crystal molecules is disordered is shown by a mesh bottom extending in the extending direction of the electrode branch 13A.

Moreover, if the liquid crystal panel currently used has a reverse twist phenomenon, there is a problem that it does not return to its original state due to natural placement. This is because the difference in the expansion between the upper portion and the lower portion of the pixel is stabilized by the combination of the central portion of the pixel, so that the alignment direction of the liquid crystal molecules located in the region 43 does not return to the original state. As a result, the region 43 in which the reverse twist phenomenon occurs may have a problem of being a residual image (that is, displaying unevenness) and never being visually recognized. Hereinafter, this residual picture is referred to as a reverse twist line.

Incidentally, in the two electrode branches 13A extending directly from the contact portion 13C, the reverse twist line easily remains. In Fig. 5, the two reverse twist lines on the center side of the pixel area are expressed more emphasized than the reverse twist lines on both sides.

Here, the inventors of the present invention proposed a liquid crystal panel having first and second substrates that are opposed to each other with a predetermined distance therebetween, and a liquid crystal layer and alignment between the first and second substrates. a film, a counter electrode pattern formed on the first substrate side, and a pixel electrode pattern formed by a plurality of electrode branches on the first substrate side, and connecting the plurality of electrode branches transversely from the contact point A portion of the plurality of extended electrode strips is connected to a liquid crystal panel of a pixel electrode pattern formed near the contact point.

Further, the pixel electrode pattern and the target electrode pattern may be formed on the same layer surface or may be formed on different layer surfaces. That is, a liquid crystal panel of a horizontal electric field display type may have a slit in the pixel electrode regardless of the cross-sectional structure of the pixel region. Further, it is preferable that the angle between the extending direction of the slit formed by the plurality of electrode branches constituting the pixel electrode pattern and the alignment direction of the liquid crystal is set to 7 or more.

As described above, the inventors of the present invention form a partial connecting branch in which a plurality of electrode branches are connected transversely in the vicinity of the contact point where the alignment stability is weak. Therefore, even when the liquid crystal is pressed by the external pressure, the erroneous direction generated in the vicinity of the contact point can be grown along the electrode to the center of the pixel, and the vicinity of the contact point and the partial branch can be sealed. between. As a result, the occurrence of display unevenness (reverse twist line) due to external pressure can be minimized.

[Best form for implementing the invention]

Hereinafter, the best mode of the present invention will be described in the order shown below.

(A) Appearance example and panel structure of liquid crystal panel module

(B) pixel structure example 1: occasion with single domain structure

(C) pixel structure example 2: occasion with suspected dual-domain structure

(D) pixel structure example 3: occasion with dual domain structure

(E) pixel structure example 4: a case with a dual domain structure

(F) pixel structure example 5: other profile structure

(G) pixel structure example 6: other cross-section structures

(H) pixel structure example 7: other pixel structure examples

(I) Other forms

Further, well-known or known techniques in the technical field are applied to portions that are not specifically illustrated or described in the specification. Further, the examples of the following description are merely examples of the invention, and the scope of the invention is not limited thereto.

(A) Appearance example and panel structure of liquid crystal panel module

FIG. 6 shows an example of the appearance of the liquid crystal panel module 51. The liquid crystal panel module 51 has a structure in which the support substrate 53 is bonded to the opposite substrate 55. The support substrate 53 is made of glass, plastic or other substrate. The opposite substrate 55 is also made of glass, plastic or other transparent member. The opposite substrate 55 is a member that seals the surface of the support substrate 53 with a sealing material.

Further, the transparency of the substrate may be such that the light exit side is ensured, and the other substrate may be an opaque substrate.

In addition, in the liquid crystal panel 51, an FPC (Flexible Printed Circuit Board) 57 for inputting an external signal or a driving power source is disposed as necessary.

FIG. 7 shows an example of the system configuration of the liquid crystal panel module 51. The liquid crystal panel module 51 is provided on the lower glass substrate 61 (corresponding to the glass substrate 5 of FIG. 1), and is provided with a pixel array unit 63, a signal line driver 65, a gate line driver 67, a dynamic controller 69, and the like. Composition. In the case of this type of example, the driving circuit of the pixel array unit 63 is formed as one or a plurality of semiconductor integrated circuits, and is mounted on a glass substrate.

In other words, the pixel array unit 63 has a matrix structure in which one pixel on the display is arranged in a matrix of M rows×N columns. Further, in this specification, the term "row" means a pixel sequence composed of 3 × N sub-pixels 71 arranged in the X direction in the drawing. In addition, the column refers to a pixel column composed of M sub-pixels 71 arranged in the Y direction in the drawing. Of course, the values of M and N depend on the display resolution in the vertical direction and the display resolution in the horizontal direction.

In addition, the signal line driver 65 is used to apply the signal potential Vsig corresponding to the pixel tone to the signal line DL. In the case of this type of example, the signal line DL is wired so as to extend in the Y direction in the figure.

The gate line driver 67 is provided for applying a control pulse for supplying the timing of the signal potential Vsig to the scanning line WL. In the case of this type of example, the scanning line WL is wired so as to extend in the X direction in the drawing.

Here, in the sub-pixel 71, a thin film transistor (not shown) is formed, the gate electrode thereof is connected to the scanning line WL, one of the main electrodes is connected to the signal line DL, and the other side of the main electrode is connected to the drawing. Prime electrode 13.

The dynamic controller 69 is a circuit device for supplying a drive pulse to the signal line driver 65 and the gate line driver 67.

(B) pixel structure example 1

An example of a pixel structure is shown in FIG. This pixel structure is used in an FFS (Fringe Field Switching) type liquid crystal panel.

That is, the cross-sectional structure of the pixel region becomes the structure shown in FIG. In other words, the counter electrode 15 is disposed on the lower layer side of the pixel electrode 13 so as to cover the entire pixel region.

The basic structure of the pixel structure shown in Fig. 8 is the same as the pixel structure shown in Fig. 2. In other words, the pixel electrode 13 has a structure in which both ends of the five electrode branches 13A processed into a comb shape are connected by a connecting portion 13B.

Further, the pixel electrode 13 has a contact portion 13C on the upper end side in the figure of the pixel region. The contact portion 13C is connected to a thin film transistor (not shown) by a contact point 25 formed near the center thereof.

Further, the contact portion 13C is continuous with the connection portion 13B on one end side, and is connected to the three electrode branches 13A at the other end portion.

Further, the three electrode branches 13A here are electrode branches 13A other than the two electrode branches 13A at the both ends among the five electrode branches 13A.

However, the contact portion 13C has a large pattern area. Therefore, the alignment stability of the boundary portion between the two slits 31 formed by the three electrode branches 13A directly connected to the contact portion 13C is likely to be weak. The weak stability of the alignment means that the reverse twist in the case where the liquid crystal is pressed is also easy to grow.

Here, in the case of the pixel structure example shown in FIG. 8, a portion of the connecting branch 81 between the three electrode branches 13A extending directly from the contact portion 13C is connected to the position near the contact portion 13C. By the partial connection of the branches 81, the two slits 31 formed by the three electrode branches 13A located on the center side of the pixel region can be physically divided into two regions.

When the liquid crystal is pressed, the two slits 31 are slits in which the reverse twisting tends to occur remarkably.

However, even if the liquid crystal is pressed down by the partial connection branch 81, the growth of the reverse twist can be left in the slit 31 on the side of the contact portion 13C, and it is not possible to be near the center of the pixel region. Fig. 9 shows a state in the case where the liquid crystal is pressed by an external pressure.

As can be seen by comparing FIG. 9 with FIG. 5, in the pixel region where the partial connection branch 81 is formed, the reverse twist line remaining in the pixel region is greatly reduced. In particular, the reverse twist line generated near the center of the pixel area can be completely disappeared or substantially reduced.

As a result, the display quality of the entire liquid crystal panel can be greatly improved by the use of the pixel structure.

Further, it is preferable that the gap formed between the contact portion 13C and the partial connecting branch 81 is as narrow as possible. For example, it is preferred to narrow the gap near the manufacturing limit. Because the narrower the gap, the area of the pixel area where the alignment restriction force acts can be increased.

Similarly, the partial connecting branch 81 may be divided into two as long as the area is wide, and the width of the pattern is preferably as small as the manufacturing limit.

(C) pixel structure example 2

A second pixel structure example is shown in FIG. This pixel structure example is also assumed to be used in an FFS (Fringe Field Switching) type liquid crystal panel.

The basic pattern structure of the pixel electrode 13 is the same as the above-described pixel structure example (Fig. 8). In other words, the pixel electrode 13 is composed of five electrode branches 13A, a connecting portion 13B, a contact portion 13C, and a partial connecting branch 81.

However, in the case of the above-described pixel structure example (Fig. 8), any of the signal line 21 and the electrode branch 13A is exemplified as being formed in parallel with the Y-axis direction.

On the other hand, in the case of the pixel structure example shown in FIG. 10, the wiring in the pixel region is formed to be inclined in the Y-axis direction, which is different from the above-described pixel structure example.

Further, this oblique direction is formed to be reversed between two pixel regions located above and below the Y-axis direction. That is, a pattern in which the pattern inclined in the clockwise direction in the Y-axis direction is inclined in the counterclockwise direction is alternately arranged along the Y-axis direction. In other words, the pixel region of this type of example has an upper and lower mirror structure for the scanning line 23 extending in the X-axis direction.

Further, in Fig. 10, the pattern of the pixel region is mainly displayed when the Y-axis direction is inclined in the clockwise direction. That is, the alignment direction of the alignment film 11 is parallel to the Y-axis direction. That is, in this pixel region, the liquid crystal molecules rotate counterclockwise when an electric field is applied.

Of course, above the pixel region mainly shown in FIG. 10, the pattern of the pixel region is formed into a pixel region which is inclined in the counterclockwise direction in the Y-axis direction. Of course, in this pixel region, the liquid crystal molecules rotate clockwise when an electric field is applied.

In this manner, the direction of rotation of the liquid crystal molecules is opposite to each other in the upper and lower pixel regions, whereby a liquid crystal panel having a wide viewing angle can be realized.

Moreover, the pixel structure shown above constitutes a suspected dual-domain structure.

Hereinafter, a desired relationship between the alignment direction of the liquid crystal layer 7 and the extending direction of the slit 31 formed by the electrode branch 13A will be described. Further, the alignment direction of the liquid crystal layer 7 (also referred to as "the alignment direction of the liquid crystal") is defined as the direction in which the dielectric ratio of the liquid crystal is in the opposite direction to the direction in which the dielectric constant is large.

In the pixel structure shown in FIG. 10, it is indicated that the alignment direction of the alignment film 11 and the direction in which the slit 31 formed by the electrode branch 13A and the liquid crystal layer 7 have an intersection angle α of 7 or more. structure.

This value is determined by the following experiment. Hereinafter, the characteristics confirmed by the inventors of the present invention and the like will be described.

First, in FIG. 11, the characteristics confirmed between the extending direction of the slit 31 and the alignment direction of the liquid crystal layer 7 are shown. In Fig. 11, the relationship between the crossing angle α and the time until the display unevenness disappears is shown. The horizontal axis of Fig. 11 shows the crossing angle α between the extending direction of the slit 31 and the alignment direction of the liquid crystal layer 7, and the vertical axis of Fig. 11 shows the time until the unevenness disappears.

From the experimental results shown in Fig. 11, when the crossing angle α was less than 7°, it was confirmed that the display unevenness (mura) caused by the reverse twist phenomenon did not naturally disappear.

On the other hand, when the intersection angle α is 7° or more, it is confirmed that the display unevenness (mura) due to the reverse twist phenomenon can naturally disappear. This is the reason why the crossing angle α is indicated as 7° or more in FIG.

Further, when the crossing angle α is 7°, the time required to display the disappearance of the unevenness is 3.5 seconds. Further, as a result of the experiment, it was confirmed that the larger the crossing angle α is, the shorter the time until the display unevenness disappears.

For example, when the crossing angle α is 10°, it is confirmed that the display unevenness disappears for 3 seconds. Further, for example, when the crossing angle α is 15°, it is confirmed that the display unevenness disappears for 2.5 seconds. Further, for example, when the crossing angle α is 20°, it is confirmed that the display unevenness disappears for 1.5 seconds.

From these, it can be seen that the larger the crossing angle α, the higher the alignment regulating force of the liquid crystal molecules of the liquid crystal panel of the horizontal electric field display type.

In Fig. 12, the results observed between the crossing angle α and the degree of display unevenness are shown. The horizontal axis of Fig. 12 is the intersection angle α between the extending direction of the slit 31 and the alignment direction of the liquid crystal layer 7, and the vertical axis of Fig. 12 shows the degree of visual confirmation of unevenness.

As shown in Fig. 12, when the crossing angle α is 10 or more, it is confirmed that the display unevenness cannot be seen from any angle. Further, when the crossing angle α is 5°, it is confirmed that slight display unevenness is observed when the display screen is viewed from the oblique direction. Further, the cross angle α is in the range of 5° or more and less than 10°, and it is confirmed that the visual confirmation is changed little by little as shown in FIG. 12 .

However, it is not the larger the cross angle α, the better.

The confirmed transmission characteristics are shown in FIG. Further, the horizontal axis of Fig. 13 is the intersection angle α between the extending direction of the slit 31 and the alignment direction of the liquid crystal layer 7, and the vertical axis of Fig. 13 is the relative transmittance. That is, in Fig. 13, when the crossing angle α is 5°, it is expressed as 100%.

In the case of Fig. 13, when the crossing angle α is 5°, the transmittance becomes maximum, and when the crossing angle α is 45°, the transmittance becomes minimum. Further, when the crossing angle α is 45°, the relative transmittance is about 64%.

As shown in FIG. 13, the relationship between the crossing angle α and the relative transmittance is considered to be substantially linear. From the viewpoint of the transmittance, the smaller the crossing angle α is, the more advantageous it is to display the brightness.

From the above characteristics, the inventors of the present invention considered that the intersection angle α of the extending direction of the slit 31 and the alignment direction of the liquid crystal layer 7 is preferably 7° or more and 15° or less. When this condition is satisfied, both the relative transmittance and the time until the display unevenness disappears can be maintained in a good state.

Thereby, even if the arrangement of the liquid crystal molecules is disturbed due to the reverse twist phenomenon caused by the finger pressure or the like, the liquid crystal panel which can be naturally eliminated within a few seconds can be realized.

(D) pixel structure example 3

A third pixel construction example is shown in FIG. This pixel structure is also used in an FFS (Fringe Field Switching) type liquid crystal panel.

However, in the third pixel structure, a case where a dual-domain structure is employed in one pixel region will be described. In other words, the pixel electrode 13 is folded in the vicinity of the center of the Y-axis direction in the pixel region (the rectangular region indicated by the broken line in the drawing).

Further, although the number of flexion points in Fig. 14 is one, it is also possible to provide two or more buckling points to have a multi-domain structure.

Here, the pixel structure shown in FIG. 14 is configured such that the imaginary line extending from the buckling point in the X-axis direction is the upper and lower mirror structure. However, the contact portion 13C or the partial joint branch 81 is one in the pixel region. That is, these are not objects of the mirror structure. Further, in the upper and lower mirror surface structure, not only the pixel electrode 13, but also the signal line 21 is included.

Further, in the case of this condition, the intersection angle α of the alignment direction of the liquid crystal layer 7 and the extending direction of the slit 31 is also 7° or more. Of course, it is preferable that the crossing angle is 7° or more and not 15° from the viewpoint of overall display performance. Further, the alignment direction of the alignment film 7 is assumed to be parallel to the Y-axis direction.

In the case of the pixel structure having the dual-domain structure, the rotation directions of the liquid crystal molecules in the upper half and the lower half of the pixel region are reversed. That is, in the upper part of the picture of the pixel area, the liquid crystal molecules are rotated counterclockwise by the application of the electric field, and the liquid crystal molecules are rotated clockwise by the application of the electric field in the lower half of the picture of the pixel area. .

In this manner, the direction of rotation of the liquid crystal molecules is reversed, and the amount of light per one pixel can be made uniform regardless of the angle from which the display screen is viewed. That is, a liquid crystal panel having a wider viewing angle than the first pixel structure can be realized.

Of course, as described above, the relationship between the alignment direction of the liquid crystal layer 7 and the extending direction of the slit 31 is optimized. That is, even if the arrangement of the liquid crystal molecules is disturbed due to the reverse twist caused by the finger pressure or the like, it can be naturally eliminated within a few seconds.

(E) pixel structure example 4

A fourth pixel construction example is shown in FIG. This pixel structure corresponds to a modification of the dual-domain structure shown in FIG. That is, the basic pixel structure corresponding to the pixel structure shown in FIG. 14 is the same as the pixel structure in which the two-field structure is employed in one pixel.

The difference is that the branching 13D of the bending points of the electrode branches 13A is connected to each other in a crosswise manner.

The reason is as follows. In the case of the third pixel structure shown in Fig. 14, the direction of rotation of the liquid crystal molecules in the boundary portion (portion of the buckling point) of the field is reversed. Therefore, the boundary portion of the boundary portion is weakened, and the alignment disorder is liable to occur. This alignment disorder has the possibility of affecting the disappearance of the reverse twist line phenomenon.

On the other hand, in the case of the pixel structure example shown in FIG. 15, the buckling point can be physically separated into two fields by connecting the connecting branches 13C of the five electrode branches 13A.

Therefore, the arrangement disorder of the liquid crystal molecules in the boundary portion of each field can be eliminated. As a result, the pixel structure shown in Fig. 15 can shorten the time required for the reverse twist line to disappear, which is shorter than the case of the pixel structure shown in Fig. 14.

(F) pixel structure example 5

In the above-described four pixel structure examples, an FFS type liquid crystal panel having the cross-sectional structure described in Fig. 1 will be described. In other words, a liquid crystal panel having a pixel structure in which the counter electrode 15 is disposed so as to cover the entire pixel region is described in the lower layer of the pixel electrode 13 processed into a comb shape.

However, as shown in FIG. 16, the liquid crystal panel 91 in which the counter electrode 15 is processed into a comb shape may be employed. Further, the portions corresponding to those in Fig. 16 and Fig. 1 are denoted by the same reference numerals and displayed.

In the case of FIG. 16, the electrode branch 15A of the counter electrode 15 is disposed so as to bury the gap (slit 31) of the electrode branch 13A of the pixel electrode 13.

That is, the electrode branch 15A of the counter electrode 15 is disposed so as not to overlap the electrode branch 13A of the pixel electrode 13 in the pixel region. Of course, there is no difference in the electric field formed between the pixel electrode 13 and the counter electrode 15.

(G) pixel structure example 6

In the case of the above-described respective pixel structure examples, the pixel structure of the pixel electrode 13 and the counter electrode 15 formed on different layers will be described.

However, the technique proposed by the inventors of the present invention can also be applied to a liquid crystal panel of a horizontal electric field display type in which the pixel electrode 13 and the counter electrode 15 are formed in the same layer.

An example of a cross-sectional structure corresponding to the sixth pixel structure example is shown in Fig. 17, and a plane structure example corresponding to the sixth pixel structure example is shown in Fig. 18. Further, the basic structure of the liquid crystal panel is also the same as that of the liquid crystal panel corresponding to the other pixel structure.

In other words, the liquid crystal panel 101 is composed of two glass substrates 3 and 5 and a liquid crystal layer 7 which is sealed by being inserted. The polarizing plate 9 is disposed on the outer surface of each of the substrates, and the alignment film 11 is disposed on the inner surface.

Further, in the liquid crystal panel 101 shown in FIG. 17, the pixel electrode 13 and the counter electrode 15 are formed on the glass substrate 5.

Among these, the pixel electrode 13 has a structure in which one end of the four electrode branches 13A processed into a comb shape is connected by a connecting portion 13B.

On the other hand, the counter electrode 15 in the pixel region is formed in a comb shape as in the case of Fig. 16 . In the case of Fig. 17, three electrode branches 15A are formed in the pixel region, and one end thereof is connected to the common electrode line 33. Here, the electrode branch 15A of the counter electrode 15 is formed in the same level as the pixel electrode 13 so as to be embedded in the gap of the electrode branch 13A of the pixel electrode 13. Further, as shown in FIG. 18, the common electrode line 33 is formed in a lattice shape along the signal line 21 and the scanning line 23.

As described above, in the case of the pixel structure example, the electrode branch 13A of the pixel electrode 13 and the electrode branch 15A of the counter electrode 15 are arranged in the same level, and are arranged so as to alternately appear in the X-axis direction. With this electrode structure, a radiation-like electric field is generated between the electrode branch 13A of the pixel electrode 13 and the electrode branch 15A of the counter electrode 15. In Figure 17, this electric field is indicated by a dashed line.

Further, as shown in Fig. 18, in the case of the pixel structure example herein, the contact portion 13C has two electrode branches 13A extending directly. In other words, in the case of this pixel structure, the partial connection branches 81 are formed so as to connect the two electrode branches 13A to each other.

With this pixel structure, it is possible to realize a liquid crystal panel which is difficult to generate a reverse twist line in the vicinity of the center of the pixel region due to a pressure other than a finger pressure.

(H) pixel structure example 7

In the above-described six pixel structure examples, the case where the extending direction of the slit 31 formed by the electrode branch 13A of the pixel electrode 13 is parallel to the Y-axis direction or the Y-axis direction intersects at an acute angle is described.

However, the extending direction of the slit 31 formed by the electrode branch 13A of the pixel electrode 13 may be parallel to the X-axis direction or at an acute angle to the X-axis direction.

An example of such a pixel structure is shown in FIG. In addition, FIG. 19 shows an example of a pixel structure in the case where the pixel electrode 13 and the counter electrode 15 are disposed on another layer on the side of the glass substrate 5 (FIG. 1). Of course, the same pixel structure as the sixth pixel configuration example can also be considered.

Returning to the description of Figure 19. In the case of Fig. 19, the electrode branch 13A of the pixel electrode 13 is formed in parallel with the scanning line 23. Next, both ends of the electrode branch 13A are connected by a connecting portion 13B. Therefore, the slit 31 formed between the electrode branches 13A is extended in the X direction.

In the case of this pixel structure example, the alignment force is also weakened at the boundary portion between the contact portion 13C and the electrode branch 13A directly extending from the contact portion 13C.

However, by forming the partial connecting branch 81 so as to traverse between the electrode branches 13A, it is possible to effectively suppress the growth of the reverse twist line of the region when external pressure is applied, as in the case of the other pixel structure examples described above.

(I) Other forms

(I-1) substrate material

In the above description, a glass substrate is used as the substrate, but other substrates such as a plastic substrate may be used.

(I-2) Orientation direction of alignment film 1

In the case of the pixel structure example 1 (Fig. 8) in the above-described type of example, it is assumed that the alignment direction of the liquid crystal layer 7 and the extending direction of the slit 31 intersect at an acute angle of about 3 degrees.

Of course, when the crossing angle α is 7° or more, similarly to the pixel structure example 2 (Fig. 10), it is expected that the effect of the reverse twist line generated can be eliminated by natural placement.

(I-3) Orientation direction of alignment film 1

In the above-described example, in the case of the pixel structure example 2 (FIG. 10), the pixel structure example 3 (FIG. 14), and the pixel structure example 4 (FIG. 15), the alignment direction and the slit of the liquid crystal layer 7 will be described. A preferable example is the case where the crossing angle α formed between the extending directions of 31 is 7 or more.

However, the crossing angle α may also be less than 7°. In this case, the display unevenness may remain. However, as shown in FIG. 9, the growth of the reverse twist line near the center of the pixel region can be effectively improved. Therefore, the improvement effect of the display quality can be expected.

(I-4) Product example

In the foregoing description, various pixel structures in which a lateral electric field can occur will be described. Here, an electronic device having a liquid crystal panel (a state in which a driving circuit is not mounted) or a liquid crystal panel module (a state in which a driving circuit is mounted) having a pixel structure according to these types of examples is mounted will be described.

FIG. 20 shows an example of the conceptual configuration of the electronic device 111. The electronic device 111 is constituted by a liquid crystal panel 113 having the above-described pixel structure, a system control unit 115, and an operation input unit 117. The processing content executed by the system control unit 115 differs depending on the product type of the electronic device 111.

Further, the configuration of the operation input unit 117 also differs depending on the product type, and is constituted by, for example, a GUI (picture type user interface), a switch, a button, a cursor device, and other operators.

Further, the electronic device 111 is not limited to a specific field of equipment as long as it has a function of displaying an image or a video generated in the device or input from the outside.

Fig. 21 shows an example of the appearance of a case where another electronic device is a television receiver. A display screen 127 including a front panel 123, a filter glass 125, and the like is disposed on the front surface of the casing of the television receiver 121. The portion of the display screen 127 corresponds to the liquid crystal panel described in the example.

Further, in such an electronic machine 111, for example, a digital camera can be assumed. FIG. 22 shows an example of the appearance of the digital camera 131. Fig. 22(A) shows the appearance side of the front side (the subject side), and Fig. 22(B) shows the appearance side of the back side (photographer side).

The digital camera 131 is composed of a protective casing 133, a photographing lens portion 135, a display screen 137, a control switch 139, and a shutter button 141. The portion of the display screen 137 corresponds to the liquid crystal panel described in the example.

Further, in such an electronic machine 111, for example, a camera can be assumed. FIG. 23 shows an example of the appearance of the camera 151.

The camera 151 is configured by photographing the subject's photographing lens 155, the photographing start/stop button 157, and the display screen 159 in front of the main body 153. The portion of the display screen 159 corresponds to the liquid crystal panel described in the example.

Further, in such an electronic machine 111, for example, a portable terminal device can be assumed. Fig. 24 is a view showing an example of the appearance of a mobile phone 161 as a portable terminal device. The mobile phone 161 shown in Fig. 24 is of a folded type, and Fig. 24(A) shows an example of the appearance of the state in which the casing is opened, and Fig. 24(B) shows an example of the appearance of the state in which the casing is folded.

The mobile phone 161 is composed of the upper side casing 163, the lower casing 165, the connecting portion (in this example, the hinge portion) 167, the display screen 169, the auxiliary display screen 171, the photographing lamp 173, and the photographing lens 175. The portion of the display screen 169 and the auxiliary display screen 171 corresponds to the liquid crystal panel described in the example.

Further, in such an electronic machine 111, for example, a computer can be assumed. FIG. 25 shows an appearance example of the notebook computer 181.

The notebook computer 181 is composed of a lower casing 183, an upper casing 185, a keyboard 187, and a display screen 189. The portion of the display screen 189 corresponds to the liquid crystal panel described in the example.

Others, the electronic device 111 is also conceivable as a projector, an audio reproduction device, a game machine, an electronic book, an electronic dictionary, or the like.

(I-5) Other

For the above-described types of examples, various modifications are conceivable within the scope of the gist of the invention. Further, various modifications and application examples created or combined according to the description of the present specification are also conceivable.

11. . . Orientation film

13. . . Pixel electrode

13A. . . Electrode branch

13B. . . Linkage

13C. . . Contact

15. . . Counter electrode

15A. . . Electrode branch

25. . . Contact point

31. . . Slit

81. . . Partial link

Fig. 1 is a view showing an example of a cross-sectional structure of a liquid crystal panel of a horizontal electric field display type.

Fig. 2 is a view showing an example of a planar structure of a liquid crystal panel of a horizontal electric field display type.

Fig. 3 is a view showing an example of a cross-sectional structure in the vicinity of a contact point.

Figure 4 is a diagram illustrating the disclination.

Fig. 5 is a view for explaining a reverse twist phenomenon.

Fig. 6 is a view showing an example of the appearance of a liquid crystal panel module.

Fig. 7 is a view showing an example of a system configuration of a liquid crystal panel module.

Fig. 8 is a view showing a first pixel structure example (planar structure).

Fig. 9 is a view showing an example of occurrence of a reverse twist line.

Fig. 10 is a view showing a second pixel structure example (planar structure).

Fig. 11 is a view showing the relationship between the size of the crossing angle and the disappearance time of display unevenness (mura).

Fig. 12 is a view showing the relationship between the size of the crossing angle and the degree of display unevenness.

Fig. 13 is a view showing the relationship between the size of the crossing angle and the relative transmittance.

Fig. 14 is a view showing a third pixel structure example (planar structure).

Fig. 15 is a view showing a fourth pixel structure example (planar structure).

Fig. 16 is a view showing a fifth pixel structure example (cross-sectional structure).

Fig. 17 is a view showing a sixth pixel structure example (cross-sectional structure).

Fig. 18 is a view showing a sixth pixel structure example (planar structure).

Fig. 19 is a view showing a seventh pixel structure example (planar structure).

Figure 20 is a diagram showing the system configuration of an electronic device.

Fig. 21 is a view showing an example of the appearance of an electronic device.

Fig. 22 is a view showing an example of the appearance of an electronic device.

Fig. 23 is a view showing an example of the appearance of an electronic device.

Fig. 24 is a view showing an example of the appearance of an electronic device.

Fig. 25 is a view showing an example of the appearance of an electronic device.

13. . . Pixel electrode

13A. . . Electrode branch

13B. . . Linkage

13C. . . Contact

twenty one. . . Signal line

twenty three. . . Scanning line

25. . . Contact point

31. . . Slit

81. . . Partial link

Claims (4)

A liquid crystal panel characterized in that: a first and a second substrate which are disposed to face each other at a constant distance, a liquid crystal layer sealed between the first and second substrates, and an alignment film are formed in the first a counter electrode pattern on the substrate side and a pixel electrode pattern which is a pixel electrode pattern formed by a plurality of electrode branches on the first substrate side, and the plurality of electrode strips are laterally A part of the connecting branch of the plurality of electrode branches extending from the contact point is connected to the vicinity of the contact point. The liquid crystal panel of claim 1, wherein the pixel element pattern and the counter electrode pattern are formed on the same layer surface. The liquid crystal panel of claim 1, wherein the pixel element pattern and the counter electrode pattern are formed on different hierarchical planes. The liquid crystal panel of claim 2, wherein the intersection angle of the slit formed by the plurality of electrode branches constituting the pixel electrode pattern and the alignment direction of the liquid crystal is formed to be 7 or more.